Background: Since 1984 MRI gel dosimetry has been introduced as a potential technique for 3D dosimetry. Most of the studies have measured R1 (1/T1) or R2 (1/T2) properties of the gel depending on the gel type. We have studied image intensity change in the Fricke gel by different MRI protocols. Materials and Methods: Gel Dosimeters contain 0.4 mM ferrous sulphate, 1 mM NaCl, 50 mM H2SO4 and 1% b...